Cases of hepatitis C are on the increase in Dunedin, largely attributed to the rising popularity of backyard tattooing.
Hepatitis C Resource Centre Otago chairwoman Margaret Fraser said an estimated 1% or more of the city's population had the highly contagious blood-borne virus and many were ignorant of the fact.
Mrs Fraser said of the more than 50,000 New Zealanders believed to be infected with hepatitis C, only about 20,000 had been diagnosed.
"So there's about 30,000 people walking around infected with hepatitis C who don't even know it."
Mrs Fraser - a clinical nurse specialist who treats people with the virus at Dunedin Hospital - said there had been a noted increase in local hepatitis C cases.
The ease of obtaining tattoo equipment and the rising number of amateur unregulated tattooists may be to blame, she said.
"People need to know that there are unsafe tattoos being done in Dunedin and people are being infected with hepatitis C.
People are buying tattoo equipment and doing tattoos at home and tattooing their friends."
Mrs Fraser said in December 2010 a single New Zealand online auction website advertised more than 900 pieces of tattooing equipment for sale.
Many amateur tattooists did not realise the ease with which hepatitis C could be passed from one person to another, she said.
"Hepatitis C is survivable on surfaces for up to four months and it's incredibly infectious.
You have to assume everybody's blood is potentially infectious."
Tattooists must clean and sterilise all equipment, use new ink with each tattoo and make sure surfaces are sterile to avoid the spread of hepatitis C, she said.
Certified tattooists regulated by the Dunedin City Council were not a problem.
Hepatitis C symptoms were mostly vague and similar to flu symptoms, although the virus was easy to detect, she said.
"If anybody thinks they have been at risk of getting hepatitis C they should get a blood test from their GP."
Those at the Hepatitis C Resource Centre Otago were also warning travelling Kiwis not to be tempted by cheaper tattoos overseas.
Co-ordinator Allison Beck said even roadside barbers could spread the virus if razors and shaving blades were not sterilised or replaced. Body piercing, dentistry and other medical procedures posed an equal risk.
In one case, a Dunedin woman contracted hepatitis C by getting a pedicure while on holiday in Thailand, she said.
"We seem to think we are bulletproof, especially with blood-borne viruses and we love getting tattoos as a nation. It's not just drug users who are contracting hepatitis C, the virus can be spread through sporting injuries, boxing, road accidents, tattooing and body piercing - any way there is blood to blood contact," Ms Beck said.
Hepatitis C
• A highly infectious virus affecting primarily the liver.
• Spread by blood-to-blood contact.
• Has infected an estimated 130 million-170 million people worldwide.
• Can be treated with medication.
• Between 50% and 80% of people treated are cured.
• Is a leading cause of liver transplantation.
• Cannot be vaccinated against.
• Symptoms include decreased appetite, fatigue, nausea, muscle or joint pain and weight loss.
• About 80% of those exposed to the virus develop a chronic infection.
